Retail Insane is a piece of cake. Fury AI works on all difficulty levels, across the board. It makes things livelier as much as it makes them harder.
This is irrevelant as it is neither the way

would have designed the game to be played, nor the way the majority of players would have/do played/play it.
Are you aware that on difficulties below insane, the player gets a magical damage buffer and the number of attackers is actually hard-capped?
This is irrevelant as it is neither the way

would have designed the game to be played, nor the way the majority of players would have/do played/play it.
Or do you mean that they MEANT for all those extra missiles besides Tempests and maybe Rockeyes to almost never be used? That they'd drop in a whole sequence of a fighter several missions long and it'd be completely useless? That

is basically composed of idiots who put in a bunch of hard work knowing it would all be for nothing in the end? You're really going to bite the hand that gave us this game that way?
So in reality, only a few fighters and turrets can shoot at the player, and s/he magically takes 60% of the damage that everything else does?
Why not? It's a game and we're talking about what constitutes reality in the game. Your desire for absolute realism is already irrelevent considering we have subspace travel, stealth fighters in space, conventional weapons with kiloton and megaton yields that are smaller than a human body, and everything takes place at ludicriously low speeds. You want reality, go play I-War or something. Your arbitrary skepticism does you no credit here.
Tempests are still better on medium. Their DPS is crazy!
And as anyone who exists outside an MMO can tell you, DPS isn't everything. Tactical factors typically dominate in a direct confrontation. It's great that your own are different from everyone else's, but you're failing your statistics classes and common sense by assuming you constitute any kind of norm.
But I suggest trying out Insane. You'll probably surprise yourself. And until you've played Insane, you'll be working off bad data.
Arbitrary decision. Prove this is true in light of the fact most players of this game would never touch insane and

would have known this.
For that matter, you have no idea what level I typically play the game on, or how good at it I am. You know what level I
test it on, because I've told you, but honestly, you're just talking out of your ass accusing me of anything related to skill or jealousy of.